    // 轮播
        //t代表banner切换的时间间隔；int代表banner渐变的时长；auto代表banner是否自动播放
        function Banner(_t, _int, _auto) {
            this.bannerContainer = null;
            this.bannerBox = null;
            this.allBannerItem = null;
            this.bannerIndexBox = null;
            this.allBannerIndexItem = null;
            this.bannerInt = null;
            this.index = 0;
            this._t = _t;
            this._int = _int;
            this._auto = _auto;
            this.canChange = true;
        }
        Banner.prototype = {
            constructor: Banner,
            getElement: function () {
                this.bannerContainer = document.getElementsByClassName("banner_container")[0];
                this.bannerBox = document.getElementById("banner-box");
                this.allBannerItem = this.bannerBox.getElementsByTagName("li");
                this.bannerIndexBox = document.getElementById("banner-index-box");
                this.allBannerIndexItem = this.bannerIndexBox.getElementsByTagName("li");
            },
            bannerInit: function () {
                this.getElement();
                this.bannerWidthInit();
                (this._auto) && (this.bannerAutoPlay());
                this.bannerIndexClick();
            },
            bannerWidthInit: function () {
                var that = this;
                that.setBannerWidth();
                window.onresize = function () {
                    that.setBannerWidth();
                };
            },
            setBannerWidth: function () {
                var windowW = document.documentElement.clientWidth;
                if (windowW < 1000) {
                    this.bannerContainer.style.height = 1000 / 3 + "px";
                } else {
                    this.bannerContainer.style.height = windowW / 3 + "px";
                }
            },
            bannerChange: function (index, nextIndex) {
                var that = this;
                if (that.canChange) {
                    that.canChange = false;
                    var item = that.allBannerItem;
                    item[nextIndex].style.zIndex = "2";
                    item[index].className += " banner-tran";
                    item[index].style.opacity = "0";
                    setTimeout(function () {
                        item[nextIndex].style.zIndex = "3";
                        item[index].style.zIndex = "1";
                        item[index].className = item[index].className.replace(/\sbanner-tran/, "");
                        item[index].style.opacity = "1";
                        that.index = nextIndex;
                        that.canChange = true;
                    }, that._int);
                }
            },
            bannerAutoPlay: function () {
                var that = this;
                that.bannerInt = setInterval(function () {
                    var nextIndex = that.index + 1 === that.allBannerItem.length ? 0 : that.index + 1;
                    that.allBannerIndexItem[that.index].className = "";
                    that.allBannerIndexItem[nextIndex].className = "banner-index-active";
                    that.bannerChange(that.index, nextIndex);
                }, that._t);
            },
            bannerIndexClick: function () {
                var that = this;
                var item = that.allBannerIndexItem;
                for (var i = 0; i < item.length; i++) {
                    item[i].index = i;
                    item[i].addEventListener("click", function () {
                        if (this.className.indexOf("banner-index-active") === -1 && that.canChange) {
                            clearInterval(that.bannerInt);
                            (that._auto) && (that.bannerAutoPlay());
                            document.getElementsByClassName("banner-index-active")[0].className = "";
                            this.className = "banner-index-active";
                            that.bannerChange(that.index, this.index);
                        }
                    })
                }
            }
        };
        var banner = new Banner(6000, 500, true);
        banner.bannerInit();
